Effect of Volcanic Ash and Natural Pozzolana on mechanical properties of sustainable cement concrete: A comprehensive review

Environmental degradation is on the rise due to escalating pollution caused by raw material depletion and the increasing demand for concrete products. Consequently, researchers and scientists have dedicated significant efforts towards developing sustainable, eco-friendly concrete using renewable materials. Among these materials, Volcanic Ash (VA) and other Natural Pozzolana (NP) types have emerged as promising Supplementary Cementitious Materials (SCMs). VA and NP types play a crucial role in reducing costs, energy consumption, and environmental impacts associated with cement production. Thus, it is imperative to investigate the characteristics of VA and NP and their influence on the performance of concrete and cement mortar. This paper presents a comprehensive review of previous studies examining the effect of VA and other NP types on the mechanical properties of concrete while evaluating their chemical, physical, and microstructure characteristics. The findings from these studies indicate that the properties of concrete primarily depend on the characteristics and quantities of NP employed. Notably, silica dioxide (SiO2) comprises the predominant component in VA compositions. In most cases, an increase in VA and NP content within concrete mixtures leads to a reduction in strength. Finally, recommendations and suggestions for future research are provided to enhance concrete properties and achieve the development of sustainable construction materials.